how does the charge pump work MC33091

Discussion in 'The Projects Forum' started by frpr666, Jul 12, 2011.

  1. frpr666

    Thread Starter Active Member

    Feb 2, 2010
    Replacing 4pcs. old MC33091
    I can't find where to buy MC33091. Now they work as full bridge mosfet driver.
    The idea is replace them (4pcs.) with some new IC, for example one HIP4080.
    But I don't know how does the charge pump work for high side in MC33091 IC.
    Does anybody know that?
  2. shortbus

    AAC Fanatic!

    Sep 30, 2009
    Here is a link showing a charge pump for a high side driver, page #18, fig. 16;

    Basically it is a capacitor and two diodes. When the one side of the cap is switched to ground, the other side charges through the first diode. When the first side of the capacitor switches to plus voltage, it causes the other side of the capacitor to discharge through the second diode. It is a voltage doubler;